The analysis in [1]} of the Schur index supports this rule.
The Schur index is defined from the superconformal index by taking the limit
\(y\rightarrow u_3q^{-\frac{1}{2}}\)  [2]}.
In this limit the index becomes
a function of only two fugacities
\(q^{\prime }=qu_3^{-\frac{1}{2}}\)  and
\(u^{\prime }=u_1^{\frac{1}{2}}u_2^{-\frac{1}{2}}\) ,
and the pole structure in the gauge fugacity integrals
is much simpler than that of the superconformal index.
In [1]} it was found that if we pick up positive poles
at each step of the gauge fugacity integrals
the correct Schur index is reproduced.
